I attempted to eat 2 plopcorn in a row and it came up with the error you can only eat one sweet every 20 minutes, I thought it was just the chocolates that were every 20 minutes.Not sure if this was supposed to happen or not.

The 20 minutes cool-down applies for all the candies.It's done to avoid "abuse" or "over-use" similar to the limit on drinks. But instead to eat x pralines at once a day, we found it more logical to add a cool-down time. Ever tried to eat a box of chocolates at once? The Pralines, aren't made to be consumed at massive amounts, but to help Seekers with a small extra to finish their set goal (like when you're one step short on the map, or forgot to feed animals, etc...).